Vacuum pump valve



f l 1,619,481 Mardi 1' 19271 E. c. oAKr-:s l

. VACUUM PUMP VALVE Filed Oct. 28, 1922 2 Sheets-Sheetl ERA/ES T CI OAKES f l 0 12" S `v MM J/A TTORNEY y Much 1,1927. y '1,619,481

I E. C. OAKES VACUUM PUMP VALVE Filed Cot?, 1922 2 ShOOtS-Sheet WITNESSES: 1

Patented Mar. l, 1927.

UNITED STATES PATENT OFFICE.

ERNEST C. OAKES, OF BLOOMFIELD, NEW JERSEY, ASSIGNOR, BY MESNE ASSIGN- MENTS, T0 EMPIRE MILKINGry MACHINE COMPANY, INC., OF ROCHESTER, NEW` YORK, A CORPORATION ,OF NEW YORK.

VACUUM PUMP VVALVE.

App-leationled October 28, 1922, Serial No. 597,471.

The invention relates to vacuum pumps and particularly to 'the valve arrangement, mechanism and its specific construction, for the particular objects of producing an eiiicieiit 'vacuum pump and which under certain conditions may be substantially noisek less, .and at the same time will be .economical for manufacture in `quantity and any wearing parts of which may be readily and economically replaced or repaired, Vand is a particular development for y vacuum lpumps involving the exacting requirementsfof a suction system used for mechanical vacuum milking machines.Y A The manufacture of a `vacuuiii pump has heretofore involvedspecial features of construction particularly Vwithy respect'to the airtight joints and in that. respect the valves.. Such has more or. less involved a complete redesigning, or radical i'nodiicaf tions in construction, and also expensive parts or expensive work for replaceu'ient and repair iii the ordinary coursevof use. While the general construction .of vacuum pumps may be varied in many respects, the essential features to secure efficiency and other advantages, as well as replacement andiepair in regular use, involve the valves for intake'and exhaust and facility of their adjustment or replacement. The difference between success and failure of a vacuum pump depends or hinges upon the efficiency of the valves and the facilityfor their replacement and repair. n l 'l i Vliile various modifications may be made in'my invention,l a particular embodiment of one form oficonstruction is shown in the accompanying' drawings in which: u

Fig. 1 is a vertical elevation, fragmentary in section, to show the baseV and valves. Fig. 2 is a vertical section of the axis of a piston, showing, on a large scale, a piston valve. n

Fig. 3 is afbottom view of the piston valve-plum Y y Fig. 4t is-a plan of the pump base'with the pump cylinders in section on the line 4-4, Fig. l. Y

Fig. 5 is a plan View of the combined piston-headivalves and'gasket.4

The pump l has cylinders 2 2 with pistons 3-3, crank-shaft 4, bearings 5. A pulley 6 secured to one end of the crank-shaft l indicates a means of turningthe crankshaft, although other suitable power delivery may involve many forms, as, for ex# ample, an internal combustion engine, .direct coupled with the crank-shaft or direct coupled to the air cylinders, `will serve to actuate the pistons to perform their function in pumping a vacuum.

The base 7 has a vacuum port 8 leading to the vacuum pipes or tubes which con? stitute the system in which a vacuum is desired,-as, for example, asysteni for milking machines, the preferred forni ,of which today involves a suction and for which vacuum piping' is provided in order to create the suction at the milk pails and at the teat cups, controlled by a suitable pulsating mechanism, in order to establish the periodic pulsating or milking effect, in conjunction with the suction draining from the cow teat into the .milk pail. For this 'purpose it iiiust be understood that the successful operation of vacuum milking` depends upon substantially uniform suction, therefore vacuuii'i, and for this vpurpose a vacuum pump meeting the exacting requirements is essential and involves the major feature of successful mechanical milkingmachines.:

`rllievacuum outlet 8 connects with the ports 9-9 which surround pedestals itl- 10,

and have superpose-d thereon `a gasket '1l which has flaps lf2-l2 formed by a circular annular slot cut into the gasket sheet V11. Thus the gasket sheet l1 determines the proximity of the cylinders 2-2 to the base 7, and likewise the limit of approach of pistons 3-3 to the base, so that upon the `assembly-and mountingof the cylinders or pump casing l upon the base 7, the relation and registering of the cylinder-heads with the base, and the valve mechanisimbecoines a matter of certainty without any specific adjustment or trial. It will be noted that the flap l2 for a substantial part of itscircumference,..as at 13, is integral with the .sheathing forming the gasket, as, forexample, gasket material known as vellumoid, which is very effective as a gasket and at the same time provides toughness vand tenacity to constitute what mayl be called a khinge at 12E-13." This permits the periodic slight rise of the flaps lQ-lQ from their respective Aseats 14, about their periphery and the top of the pedestal iO .in the centre of the port 9,` and at the same time Vsupplies Vsuiiicient strength and toughness to bridge the annie lar port space 9 and produce an air-tight joint.

In the end of the pistons 8f3 an opening is threaded to provide for a plug 15, which plug screws into the piston-head with threads 16 and has openings 17-17 providing air-ports in said plug 15 in conjunction With a valve. The valve in the piston-head comprises a valve washer 1Ta with a thin metal sheet 18, both riding` on a stud screw 1,9 screwed into the plug with a head 19 with which the disc 18 engages in order to limit its movement. This disc 18 is made very light and is sealed to the sheet or dise 17l so that both move up and down together, thereby forming the valve packing on the top surface `or valve seat 2O surrounding the ports 17-17.

By the use of a plug containing all the outlet valve mechanism at the end of the piston 3, a flush piston end is provided, vfith a minimum of clearance so that the vacuum operation in pumping is extremely effective and efficient, vvhile at the same time the plug 15 being slightly less in diameter than the periphery `1Q`L of the valve flap 12 on the base, covering the ports 9, the approach of the pistons 3 3 to the end of their down- Ward stroke insures the reseating of the valve flap 12 upon the base.

It Will thus be seen that the valve mechanisni involved inl this invention comprises a very simple and efficient piston plug for exhausting'the air from the cylinder through the piston-head, and an extremely simple air valve on the base to permit the drawing of air out of the vacuum ports 9 9 and the vacuum line or pipe connection 8. The rcmoval of the base 7 from the cylinderfheads by means of lag bolts Ta-fd, provides immediate access to the base valve as Well as the gasket to assure air-tightness of the cylinderheads With the base, and also assures a ready access to the valve plugs in the vacuum pump pistons, whereupon the holes 17-17 in the valve plug permit, if desired, ready accessibility to the plugs as a hand-hold or tool-hold to unscreiv them from the pistonheads with the facility for entire'removal of the valve plugs from the piston-heads, so that the entire air valve mechanism of the pistons may be removed and replaced, or

may be readily inspected for adjustment or repair.

` s It will thus be seen that the entire vacuum production mechanism in the vacuum pump, comprising the vacuum pipe port and uvalve in each pump-piston head, invloves eX- tremely simple construction beth as to manufacture as Well as adjustment and repair. Essentially it involves a base Vair-intake valve, as an integral part of the gasket for the cylinder-heads, and a valve plug embodying a nicely adjusted relative Weight of Washer and valve plate riding on a' simple accessible stud,while the relations of the valve plug in the piston end, in view of the particular relation thereof to the intake valve flap onthe base, insure in their co4 operation the certainty of operation With efficiency. The relation of parts also permits ofthe least possible clearance, so that besides the effectiveness, the eiiiciency of the vacuum pump is increased to a maximum.

On account of the light parts involved, and the very limited play ofthe valve flapsboth in the intake and the piston-head outlet, a minimum condition of noise exists, and as the construction provides for the utilization of soft material and the 'avoidance of metallic contact between the valve seats and valves, the construction practically provides for an entirely noiseless operating construction.

In view of the special adaptation of this vacuum pump and its valve mechanism, the avoidance of noise in connection with a dairy or coW barns is obviously advantageous, and it isv on that account'that this invention involves a most efficacious vacuum pump for the particular purposes for which it is essentially intended, that is to actuate vacuummilking machines. y

In the use of lvacuum milking machines' no absolute vacuum is required, but in thel i most successful forms noW in use about 17 inches of vacuum at the pump supplies the conditions in the vacuum system. `With this approximately 17 inches of vacuum, however, a substantial amount of air must-bem moved, as, for example, the airnecessary to produce thesuction in the pails and the actuation of the pulsating mechanism which effects the milking at the teat cups, audit may therefore be regarded, in a general way, that large volume with medium vacuum pressure is the condition prevailing for the milking machine installations.

As the actuation of the pulsators for the teat cup operation, as Well as the suction in the milk pails, must be continuous and above all must be substantially uniform,y it will be seen that for successful milking it is essential that the vacuum pump be uniform in operation and be thoroughly dependable because variations or failures lead in turn to serious trouble and damage or injury to the cows.

It Will thus be seen that the various par-V ticular requirements accomplished Vby the 'construction hereinbefore described and any cylinders, oppositely disposed pistons in said cylinders, a common base for said cylinders and a common gasket for both cylinders, an air inlet port centrally in each cylinder in the base, and a partially severed portion of the gasket above each inlet port adapted to provide an inlet valve flush with the entire surface of the cylinder head and on the approach of the piston to seat upon the base and close the inlet ports and form a spacci' coincident with the cylinder-head clearance upon the piston reaching the outer end of its stroke, whereby said valve and gasket jointly form in closed position a cushioning engagement Hush with the end and With minimum clearance from the piston when inr extreme position.

2. In an air pump, duplex cylinders, a base therefor, a combined gasket and valve sheet between the cylinder-head and the base adapted to provide a clearance sheathing an air-tight joint for the cylinder-head and having aV partially severed central flap in each cylinder-head adapted for articulation as a valve cover functioning due tothe flexibility oi the material of the sheathing in combination with duplex pistons having integral ends flush with a removable piston valve cap and movable at the end of each stroke close to the base valve and gasket throughout 'the head of the cylinder, whereby a minimum clearance is provided with parts adapted to accommodate irregularities of movement without injury to the rigid portions ci the piston.

In testimony whereof, I have signed my name to this application this 25 day of October, 1.922.

ERNEST c. oAKEs. 

